<!DOCTYPE html>
<html>
<head>
    <meta charset='UTF-8'>
    <title>框模型-边框-宽度</title>
    <style>
        div{
            border-style: solid;
            margin: 10px;
        }
        .thin{
            border-width: thin; 
        }
        .medium{
            border-width: medium;
        }
        .thick{
            border-width: thick;
        }
        .cus{
            border-width: 1px;
        }
    </style>
</head>
<body>
    <div class="thin">
        thin
    </div>
    <div class="medium">
        medium
    </div>
    <div class="thick">
        thick
    </div>
    <div class="cus">
        cus 1px
    </div>
</body>